A pneumatic radial tire has a tire carcass including a breaker band having opposite axial end portions turned back onto the outer peripheral surface of adjacent axial portions of the band. Such a configuration of the breaker band is useful for avoiding application of concentrated loads to the axial end portions of the breaker band. A band folding apparatus operable to form such a breaker band is taught in, for example, in Japanese Provisional Patent Publication No. 55-114556. A breaker band folded by the use of the band folding apparatus therein shown has a drawback in that wrinkles and unusual stresses are inevitably produced in the turned-over portions of the band and deteriorate the performance quality of the tire using such a breaker band.
It is, accordingly, an important object of the present invention to provide a method of folding a breaker band or any annular resilient band along a circumferential fold line without producing wrinkles in the vicinity of the fold line.
It is another important object of the present invention to provide a band folding apparatus adapted to put such a method into practice.